Image stabilizing device and camera

ABSTRACT

An image stabilizing device of the present invention includes: a correction lens holding member  405  to which a correction lens G 3  included in an optical system of a camera is fixed; a holding member  408  that holds the correction lens holding member so that the correction lens holding member is movable in a rectilinear direction that is an arbitrary direction in a plane orthogonal to an optical axis A of light entering the correction lens G 3  and in a rotation direction along an arc in the plane about a rotary shaft A 3  substantially parallel to the optical axis A; a driving portion for rectilinear movement  412  that applies a driving force to the correction lens holding member  405  in order to drive the correction lens holding member  405  in the rectilinear direction; and a driving portion for rotation  413  that applies a driving force to the correction lens holding member  405  in order to drive the correction lens holding member  405  in the rotation direction. According to this configuration, it is possible to provide an image stabilizing device that achieves miniaturization, while preventing a deterioration in image stabilizing performance, and a camera including the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 12/665,207,filed Dec. 17, 2009, which is a U.S. National Stage ofPCT/JP2008/001563, Jun. 18, 2008, which applications are incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to an image stabilizing device and acamera. This invention particularly relates to an image stabilizingdevice that drives a correction lens so as to perform imagestabilization and a camera including the image stabilizing device.

BACKGROUND ART

Recent years have seen the widespread use of a digital camera that usesan imaging element such as a CCD (charge coupled device) or CMOS(complementary metal-oxide semiconductor) sensor to convert an opticalimage into an electric signal and to record the electric signal in adigitized form. In a digital camera configured as above, there is a neednot only for increasing the number of pixels of a CCD or CMOS sensor butalso for improving the performance of a lens barrel that forms anoptical image on such an imaging element. Specifically, there is a needfor a lens barrel incorporating a higher-powered zoom lens system.

Meanwhile, in the field of a digital camera, there is a demand forminiaturization of a body in order to improve portability. To this end,there is a need for miniaturization of an imaging apparatus including alens barrel and an imaging element, which is believed to contributegreatly to miniaturization of the body. In an effort to achieve theabove-described miniaturization of an imaging apparatus, a so-calledbending optical system has been proposed, which achieves theminiaturization of the apparatus without changing the length of anoptical path by bending a zoom lens system at some point along theoptical path.

For example, Patent Document 1 discloses a bending optical system inwhich an optical path is bent using a reflection mirror. Specifically, alens barrel disclosed in Patent Document 1 includes on the side of asubject relative to the reflection mirror, a first lens group and asecond lens group in this order from the side of the subject, and on theside of an imaging element relative to the reflection mirror, a thirdlens group and a fourth lens group in this order from the side of thereflection mirror. The first lens group is fixed. The second lens groupand the third lens group are movable in an optical axis direction andconstitute a zoom lens system in cooperation with each other. The fourthlens group is used for focus adjustment.

Furthermore, Patent Document 2 discloses a bending optical system inwhich an optical path is bent using a prism. Specifically, a lens barreldisclosed in Patent Document 2 includes a lens group on the side of asubject relative to the prism. The lens group is movable between anin-use position and a retracted position in an optical axis direction.Moreover, the prism is movable so that a space for accommodating thelens group is secured when the lens group is in the retracted position.

Furthermore, Patent Document 3 discloses a configuration of a lens groupused in a bending optical system.

However, in order to simultaneously meet the rising demands for therealization of a high-power zoom lens system and the achievement ofminiaturization, further improvement is required.

Specifically, in each of the configurations disclosed in PatentDocuments 1 and 2, respectively, it is difficult to construct ahigh-power zoom lens system while achieving miniaturization of theapparatus. Moreover, also when adopting the lens configuration disclosedin Patent Document 3, Patent Document 3 is disadvantageous in that itdoes not disclose any configuration for achieving miniaturization of theapparatus.

Meanwhile, generally, in the case of a miniaturized imaging apparatus orin the case of including a high-power zoom lens system, there is a needfor preventing blurring of a photographed image (image blurring) fromoccurring, which mainly is due to camera shake or the like.

FIG. 18 is an exploded perspective view of an image stabilizing deviceof the prior art (see Patent Document 4). In the image stabilizingdevice shown in FIG. 18, a second lens group 101 is held by a lens frame102. The lens frame 102 is supported movably by guide shafts 103 thatguide movement in a pitching direction and in a yawing direction.Further, the lens frame 102 is provided with coils 104 a and 104 b fordriving the lens frame 102 in the pitching direction and in the yawingdirection, respectively. On a fixed base 105, magnets 106 a and 106 bare provided so as to be opposed to the coils 104 a and 104 b,respectively. When the coils 104 a and 104 b are energized, drivingforces are generated in the respective directions. The second lens group101 is driven in the pitching direction and in the yawing direction bythe driving forces generated in the coils 104 a and 104 b, respectively.The amount of shake of a lens barrel is detected by angular velocitysensors 107 a and 107 b, and based on a detection signal obtained as aresult of the detection, the coils 104 a and 104 b are energized so thatimage stabilization is performed.

-   Patent Document 1: JP 11(1999)-258678 A-   Patent Document 2: JP 2003-169236 A-   Patent Document 3: JP 2004-102089 A-   Patent Document 4: JP 2000-75338 A (FIG. 4)-   Patent Document 5: JP 7(1995)-5514 A (FIGS. 6 and 8)

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

There exists a demand for miniaturization also of an imaging apparatusincorporating an image stabilizing device. In order to meet this demand,in a conventional image stabilizing device to be incorporated in animaging apparatus, an attempt has been made to reduce the dimensionthereof in the direction of an optical axis of light entering the imagestabilizing device.

Meanwhile, there is a growing need for incorporating an imagestabilizing device in various imaging apparatuses. In this case, inorder to increase the degree of freedom in designing an imagingapparatus, there is a need not only for reducing the dimension of theimage stabilizing device in the direction of an optical axis but alsofor reducing the dimension thereof in either of directions orthogonal tothe optical axis. For example, in the case where the above-describedimage stabilizing device is incorporated in an imaging apparatus havinga bending optical system, if the conventional image stabilizing deviceis incorporated on a light emission side of a reflection mirror or aprism, the dimension of the imaging apparatus in a directionperpendicular to an optical axis of light entering the image stabilizingdevice is increased. That is, the dimension of the imaging apparatus inan optical axis direction of light entering the reflection mirror or theprism (thickness of the imaging apparatus) is increased. The reason forthis is that in the conventional image stabilizing device, two drivingportions that drive a correction lens for image stabilization in thepitching direction and in the yawing direction are arranged respectivelyin positions away from each other at 90 degrees relative to thecorrection lens.

Furthermore, as described above, in the conventional image stabilizingdevice, the guide shafts 103 are provided so that a pitching movementframe and a yawing movement frame are movable rectilinearly in thepitching direction and in the yawing direction, respectively. Therefore,spaces for installing the guide shafts 103 are required, hinderingminiaturization of the image stabilizing device.

Furthermore, not limited to the case of such an imaging apparatus havinga bending optical system, it would be more appealing to customers forimaging apparatuses to incorporate an image stabilizing device having areduced dimension in either of directions orthogonal to an optical axisso as to reduce a dimension of an imaging apparatus in any direction.

Therefore, for achieving further miniaturization of an image stabilizingdevice, an image stabilizing device has been proposed in which acorrection lens is driven to be rotated about a rotary shaft disposedsubstantially parallel to an optical axis of the correction lens (see,for example, Patent Document 5). FIGS. 19 and 20 are explodedperspective views of image stabilizing devices of the prior art.

The image stabilizing device shown in FIG. 19 is composed mainly of asupporting frame 15 to which a correction lens 16 is fixed, a supportingarm 13 that holds the supporting frame 15 so that the supporting frame15 is movable rectilinearly, and a barrel 11 that rotatably holds thesupporting arm 13. In this image stabilizing device, the supporting arm13 is driven to be rotated in a direction along an arc about a shaft 45a with respect to the barrel 11 by a permanent magnet 45 attached to thesupporting arm 13 and a coil 46 a attached to the barrel 11. Thesupporting frame 15 is driven in a direction orthogonal to an opticalaxis with respect to the supporting arm 13 by permanent magnets 47 a and47 b attached to the supporting frame 15 and a coil 49 attached to thesupporting arm 13. These configurations allow the correction lens 16 tobe movable in a plane orthogonal to the optical axis in a pitchingdirection and in a yawing direction.

Furthermore, the image stabilizing device shown in FIG. 20 is composedmainly of a supporting frame 15 to which a correction lens 16 is fixed,a supporting arm 13 that rotatably holds the supporting frame 15, and abarrel 11 that holds the supporting arm 13 so that the supporting arm 13is movable rectilinearly. In this image stabilizing device, thesupporting arm 13 is driven in a direction orthogonal to an optical axiswith respect to the barrel 11 by a coil 62 y attached to the supportingarm 13 and permanent magnets 63 y attached to the barrel 11. Thesupporting frame 15 is driven in a direction orthogonal to the opticalaxis with respect to the supporting arm 13 by a coil 62 p attached tothe supporting frame 15 and permanent magnets 63 p attached to thesupporting arm 13. These configurations allow the correction lens 16 tobe movable in a plane orthogonal to the optical axis in a pitchingdirection and in a yawing direction.

In each of the image stabilizing devices shown in FIGS. 19 and 20, asupporting frame as one of the above-described configurations is drivenin a direction along an arc about a rotary shaft. Therefore, africtional force exerted when the supporting frame is driven is reduced,and miniaturization of a driving portion having a coil and permanentmagnets is allowed. Further, when compared with the above imagestabilizing devices described in Patent Documents 1 to 4, a guide shaftfor rectilinear movement is omitted. This allows miniaturization of aguide mechanism. That is, the image stabilizing devices shown in FIGS.19 and 20 allow further miniaturization.

However, there is a concern about deterioration in image stabilizingperformance of the image stabilizing devices shown in FIGS. 19 and 20.Specifically, in the image stabilizing device shown in FIG. 19, adriving force for rotating the correction lens 16 acts on the supportingarm 13 but does not directly act on the supporting frame 15 to which thecorrection lens 16 is fixed. Further, in the image stabilizing deviceshown in FIG. 20, a driving force for rectilinearly moving thecorrection lens 16 acts on the supporting arm 13 but does not directlyact on the supporting frame 15 to which the correction lens 16 is fixed.Because of this, a lens holding member might not be held in a desiredposition depending on the dimensional precision of a portion at whichthe supporting arm 13 and the supporting frame 15 are coupled to eachother. It is feared that this might lead to a deterioration in thepositional precision of the correction lens.

As described above, there is a fear that as a result of achievingminiaturization, image stabilizing performance might deteriorate.

Furthermore, in the image stabilizing devices described in PatentDocuments 1 to 4, for example, guide shafts are fixed by adhesion.Because of this, in the course of manufacturing the image stabilizingdevices, an operation of applying and drying an adhesive is required.This renders manufacturing operations complicated, thus leading to anincrease in manufacturing cost.

It is an object of the present invention to provide an image stabilizingdevice that can achieve miniaturization and a reduction in manufacturingcost, while preventing a deterioration in image stabilizing performance,and a camera including the same.

Means for Solving Problem

An image stabilizing device according to the present invention is animage stabilizing device for correcting image blurring attributable tomovement of a camera. The image stabilizing device includes: acorrection lens holding member to which a correction lens included in anoptical system of the camera is fixed and that includes a rotary shaftsubstantially parallel to an optical axis of light entering thecorrection lens; a holding member that holds the correction lens holdingmember so that the rotary shaft is movable rectilinearly in arectilinear direction that is an arbitrary direction in a planeorthogonal to the optical axis of light entering the correction lens andso that the correction lens holding member is rotatable about the rotaryshaft in the plane; a driving portion for rectilinear movement thatapplies a driving force to the correction lens holding member in orderto drive the correction lens holding member in the rectilineardirection; and a driving portion for rotation that applies a drivingforce to the correction lens holding member in order to drive thecorrection lens holding member in the rotation direction.

A camera according to the present invention includes: the imagestabilizing unit that corrects image blurring attributable to movementof the camera; and an imaging portion that receives light that haspassed through the lens group. The image stabilizing unit includes: acorrection lens holding member to which a correction lens included inthe lens group is fixed and that includes a rotary shaft substantiallyparallel to an optical axis of light entering the correction lens; aholding member that holds the correction lens holding member so that therotary shaft is movable rectilinearly in a rectilinear direction that isan arbitrary direction in a plane orthogonal to the optical axis oflight entering the correction lens and so that the correction lensholding member is rotatable about the rotary shaft in the plane; adriving portion for rectilinear movement that applies a driving force tothe correction lens holding member in order to drive the correction lensholding member in the rectilinear direction; and a driving portion forrotation that applies a driving force to the correction lens holdingmember in order to drive the correction lens holding member in therotation direction.

Effects of the Invention

According to the present invention, it is possible to provide an imagestabilizing device that can achieve miniaturization and a reduction inpower consumption, while preventing a deterioration in image stabilizingperformance, and a camera including the same.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing an appearance of a digital camera.

FIG. 2 is a perspective view showing the appearance of the digitalcamera.

FIG. 3A is a perspective diagram schematically showing a configurationof a body portion.

FIG. 3B is a perspective diagram schematically showing the configurationof the body portion.

FIG. 3C is a perspective diagram schematically showing the configurationof the body portion.

FIG. 4 is a perspective assembly view of an imaging apparatus.

FIG. 5 is a view as seen from the side of an imaging element of theimaging apparatus.

FIG. 6 is an exploded perspective view of the imaging apparatus.

FIG. 7 is an exploded perspective view of an image stabilizing device.

FIG. 8A is a perspective view showing a holding member and engagingportions of the image stabilizing device.

FIG. 8B is a partially enlarged perspective view showing the holdingmember and the engaging portion of the image stabilizing device.

FIG. 8C is a partially enlarged perspective view showing the holdingmember and the engaging portion of the image stabilizing device.

FIG. 8D is a partially enlarged perspective view showing the holdingmember and the engaging portion of the image stabilizing device.

FIG. 8E is a partially enlarged perspective view showing the holdingmember and the engaging portion of the image stabilizing device.

FIG. 9 is a perspective view of a correction lens holding member.

FIG. 10 is an exploded perspective view of a unit showing a positionalrelationship between the holding member and the correction lens holdingmember.

FIG. 11 is an exploded perspective view of the image stabilizing devicewith the correction lens member assembled therein.

FIG. 12 is a schematic plan view of the correction lens holding memberand an electric substrate as seen from a positive side in a Y-axisdirection.

FIG. 13A is a diagram for explaining a magnet usable region and a Hallelement performance guarantee area.

FIG. 13B is a diagram for explaining the magnet usable region and theHall element performance guarantee area.

FIG. 14A is a diagrammatic view showing an engaged state between firstsupporting portions and second supporting portions.

FIG. 14B is a diagrammatic view showing the engaged state between thefirst supporting portions and the second supporting portions.

FIG. 14C is a diagrammatic view showing the engaged state between thefirst supporting portions and the second supporting portions.

FIG. 15A is a graph showing a damping effect provided by grease.

FIG. 15B is a graph showing the damping effect provided by the grease.

FIG. 15C is a graph showing a damping effect provided by grease.

FIG. 15D is a graph showing the damping effect provided by the grease.

FIG. 16 is an exploded perspective view of an image stabilizing devicewith a modified actuator magnetic circuit.

FIG. 17 is a schematic plan view of a correction lens holding member andan electric substrate as seen from a positive side in a Y-axis direction(another embodiment).

FIG. 18 is an exploded perspective view of a conventional imagestabilizing device.

FIG. 19 is an exploded perspective view of a conventional imagestabilizing device.

FIG. 20 is an exploded perspective view of a conventional imagestabilizing device.

DESCRIPTION OF THE INVENTION

An image stabilizing device according to a first invention is an imagestabilizing device for correcting image blurring attributable tomovement of a camera. The image stabilizing device includes: acorrection lens holding member to which a correction lens included in anoptical system of the camera is fixed and that includes a rotary shaftsubstantially parallel to an optical axis of light entering thecorrection lens; a holding member that holds the correction lens holdingmember so that the rotary shaft is movable rectilinearly in arectilinear direction that is an arbitrary direction in a planeorthogonal to the optical axis of light entering the correction lens andso that the correction lens holding member is rotatable about the rotaryshaft in the plane; a driving portion for rectilinear movement thatapplies a driving force to the correction lens holding member in orderto drive the correction lens holding member in the rectilineardirection; and a driving portion for rotation that applies a drivingforce to the correction lens holding member in order to drive thecorrection lens holding member in a rotation direction.

In this image stabilizing device, the correction lens holding membermoves rectilinearly in an arbitrary direction in a plane orthogonal toan optical axis and is rotated about the rotary shaft substantiallyparallel to the optical axis. Therefore, there is no need for a guidingshaft that supports a correction lens holding frame so that thecorrection lens holding frame can be driven in a rotation direction.Thus, there is no need for shafts that perform guiding in two directionsand are required for suppressing image blurring. This eliminates theneed for a process and a test for securing precision in mounting thecorrection lens holding frame (height, position, angle, parallelism,etc.). Therefore, this image stabilizing device can achieve a reductionin dimension in a direction perpendicular to a rectilinear direction andcan improve assembly processing. Thus, in the case where the imagestabilizing device according to the first invention is adopted in abending optical system, the correction lens holding frame can bedisposed so that a longitudinal direction of the image stabilizingdevice substantially coincides with a rectilinear direction of thecorrection lens holding frame, thereby making it possible to incorporatean image stabilizing device also in a bending optical system.

In addition thereto, in this image stabilizing device, driving forcesare applied directly to the lens holding member, to which the correctionlens is fixed, from the driving portion for rectilinear movement and thedriving portion for rotation, respectively. Therefore, compared with thecase where driving forces of the driving portion for rectilinearmovement and the driving portion for rotation do not act directly on thecorrection lens holding member, it is possible to prevent deteriorationin the positional precision of the correction lens, and thus to preventdeterioration in the image stabilizing performance.

Being configured as above, this image stabilizing device can achieveminiaturization, while preventing a deterioration in image stabilizingperformance. It also is possible to improve assemblability and to reducea manufacturing cost.

An image stabilizing device according to a second invention has aconfiguration in which, in the image stabilizing device according to thefirst invention, the lens holding member has a sliding groove that isprovided in an arbitrary direction in the plane orthogonal to theoptical axis of entering light. The lens holding member movesrectilinearly as a result of sliding between the sliding groove and anouter peripheral portion of the rotary shaft and is rotated about therotary shaft, thereby allowing the correction lens to move in twodirections. Herein, an optical imaging element such as a CCD is attachedto the lens holding member. Meanwhile, in the lens holding member, agroove is formed that directly restricts movement of the correction lensin the rectilinear direction. Therefore, by forming the sliding groovein parallel with either of grooves in the X- and Z-axes of the opticalimaging element such as a CCD, a correction direction of the correctionlens can be aligned with an axis of the optical element such as a CCDwith ease and precision. This makes it possible to construct ahigh-precision image stabilizing device using a simple configuration andto form the image stabilizing device so that it has a reduced thicknessin an optical axis direction.

An image stabilizing device according to a third invention has aconfiguration in which, in the image stabilizing device according to thefirst or second invention, a position detection element for rotationthat detects a position of the lens holding member in the rotationdirection further is provided. Further, the driving portion for rotationhas a magnet for rotation. Further, a magnetic flux density distributionin the rotation direction of the magnet for rotation includes a usableregion for rotation in which a magnetic flux density changes atsubstantially a constant rate. Further, when the image stabilizingdevice is seen from a direction along the optical axis, there exists astate where, in a region in which the lens holding member is movable, adetection center of the position detection element for rotationcoincides with a center line of the usable region for rotation in therotation direction. Moreover, either of the position detection elementfor rotation and the magnet for rotation is formed integrally with thecorrection lens holding member.

According to this configuration, it becomes easier for a movable area ofthe detection center of the position detection element for rotation tofall within a usable region of the magnet for rotation. Further, sinceeither of the position detection element for rotation and the magnet forrotation is formed integrally with the correction lens holding member,it is possible to prevent the precision in position detection in therotation direction from being deteriorated.

Moreover, a center of the rotary shaft of the correction lens holdingmember is disposed on the center line of the usable region for rotationof the position detection element for rotation, and thus the precisionin position detection in the rotation direction of the correction lensholding member or the correction lens can be improved.

An image stabilizing device according to a fourth invention has aconfiguration in which, in the device according to the third invention,when seen from the direction along the optical axis, in the state wherethe detection center of the position detection element for rotationcoincides with the center line of the usable region for rotation in therotation direction, a direction of the center line of the usable regionfor rotation in the rotation direction substantially coincides with (issubstantially parallel to) the rectilinear direction.

In this case, when the lens holding member is driven in the rectilineardirection, a positional shift between the detection center of theposition detection element for rotation and the center line of theusable region for rotation in the rotation direction is suppressed. As aresult, it becomes easier for the movable area of the detection centerof the position detection element for rotation to fall within the usableregion of the magnet for rotation. Thus, it is possible to prevent theprecision in position detection in the rotation direction from beingdeteriorated due to movement in the rectilinear direction.

Herein, the case where “the center line of the usable region forrotation in the rotation direction substantially coincides with (issubstantially parallel to) the rectilinear direction” refers also to, inaddition to the case where the center line completely coincides with therectilinear direction, a case where, in the state where the movable areaof the detection center of the position detection element for rotationlies within the usable region of the magnet for rotation, the centerline and the rectilinear direction are shifted from each other.

An image stabilizing device according to a fifth invention has aconfiguration in which, in the image stabilizing device according to thethird or fourth invention, when seen from the direction along theoptical axis, in a state where the optical axis of light entering thecorrection lens coincides with a center of the correction lens, thedetection center of the position detection element for rotationsubstantially coincides with the center line of the usable region forrotation in the rotation direction.

In this case, in the state where the axis of light entering thecorrection lens coincides with the center of the correction lens, itbecomes easier for the movable area of the detection center of theposition detection element for rotation to fall within the usable regionof the magnet for rotation. Thus, image stabilization can be performedin an area providing high precision in position detection in therotation direction, and thus it is possible to prevent image stabilizingperformance from being deteriorated.

Herein, the case where “the detection center of the position detectionelement for rotation substantially coincides with the center line of theusable region for rotation in the rotation direction” refers also to, inaddition to the case where the detection center completely coincideswith the center line, a case where, in the state where the movable areaof the detection center of the position detection element for rotationlies within the usable region of the magnet for rotation, the detectioncenter and the center line are shifted from each other.

An image stabilizing device according to a sixth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to fifth inventions, when seen from the direction alongthe optical axis, the rotary shaft, the center of the correction lens,and the detection center of the position detection element for rotationare disposed on substantially a straight line.

In this case, when the lens holding member is driven in the rectilineardirection, a positional shift between the detection center of theposition detection element for rotation and the center line of theusable region for rotation in the rotation direction is suppressed. As aresult, it becomes easier for the movable area of the detection centerof the position detection element for rotation to fall within the usableregion of the magnet for rotation. Thus, it is possible to preventdeterioration in the precision in position detection in the rotationdirection.

Herein, the case where “the rotary shaft, the center of the correctionlens, and the detection center of the position detection element forrotation are disposed on substantially a straight line” refers also to,in addition to the case where the rotary shaft, a center of the opticalaxis, and the detection center are disposed on a straight line, a casewhere, in the state where the movable area of the detection center ofthe position detection element for rotation lies within the usableregion of the magnet, the rotary shaft, the center of the optical axis,and the detection center are shifted from one another.

An image stabilizing device according to a seventh invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to sixth inventions, a position detection element forrectilinear movement that detects a position of the correction lensholding member in the rectilinear direction further is provided.Further, this configuration can be such that, when the image stabilizingdevice is seen from the direction along the optical axis, a line segmentconnecting the rotary shaft to a detection center of the positiondetection element for rectilinear movement substantially coincides withthe rectilinear direction.

In this case, in the state where an optical axis of light entering thecorrection lens coincides with the center of the correction lens, itbecomes easier for the movable area of the detection center of theposition detection element for rectilinear movement to fall within ausable region of a magnet for rectilinear movement. Thus, imagestabilization can be performed in an area providing high precision inthe position detection in the rectilinear direction by the positiondetection element, and thus it is possible to prevent the precision inposition detection from being deteriorated.

Herein, the case where “a line segment connecting the rotary shaft tothe detection center of the position detection element for rectilinearmovement substantially coincides with the rectilinear direction” refersalso to, in addition to the case where the line segment completelycoincides with the rectilinear direction, a case where, in the statewhere the movable area of the detection center of the position detectionelement for rectilinear movement lies within the usable region of themagnet for rectilinear movement, the line segment and the rectilineardirection are shifted from each other.

An image stabilizing device according to an eighth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to sixth inventions, a position detection element forrectilinear movement that detects a position of the correction lensholding member in the rectilinear direction further is provided.Further, the driving portion for rectilinear movement has a magnet forrectilinear movement. Further, a magnetic flux density distribution inthe rectilinear direction of the magnet for rectilinear movementincludes a usable region for rectilinear movement in which a magneticflux density changes at substantially a constant rate. Further, when theimage stabilizing device is seen from the direction along the opticalaxis, there exists a state where, in the region in which the correctionlens holding member is movable, a detection center of the positiondetection element for rectilinear movement coincides with a center lineof the usable region for rectilinear movement in the rectilineardirection.

Thus, it becomes easier for a movable area of the detection center ofthe position detection element for rectilinear movement to fall within ausable region of the magnet for rectilinear movement, and thus it ispossible to prevent the precision in position detection in therectilinear direction from being deteriorated.

An image stabilizing device according to a ninth invention has aconfiguration in which, in the image stabilizing device according to theeighth invention, when seen from the direction along the optical axis,in the state where the optical axis of light entering the correctionlens coincides with the center of the correction lens, the detectioncenter of the position detection element for rectilinear movementsubstantially coincides with the center line of the usable region forrectilinear movement in the rectilinear direction.

In this case, when the correction lens holding member is driven in therotation direction, a positional shift between the detection center ofthe position detection element for rectilinear movement and the centerline of the usable region for rectilinear movement in the rectilineardirection is suppressed. As a result, it becomes easier for the movablearea of the detection center of the position detection element forrectilinear movement to fall within the usable region of the magnet forrectilinear movement. Thus, it is possible to prevent deterioration inthe precision in position detection in the rectilinear direction.

Herein, the case where “the detection center of the position detectionelement for rectilinear movement substantially coincides with the centerline of the usable region for rectilinear movement in the rectilineardirection” refers also to, in addition to the case where the detectioncenter completely coincides with the center line, a case where, in thestate where the movable area of the detection center of the positiondetection element for rectilinear movement lies within the usable regionof the magnet for rectilinear movement, the detection center and thecenter line are shifted from each other.

An image stabilizing device according to a tenth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to ninth inventions, the driving portion for rotationhas the magnet for rotation and a coil for rotation that is disposed soas to be opposed to the magnet for rotation. Further, when the imagestabilizing device is seen from the direction along the optical axis, adistance between the rotary shaft and a center of the coil for rotationis longer than a distance between the rotary shaft and the center of thecorrection lens.

Generally, the correction lens is heavier than the correction lensholding member. Therefore, a center of gravity of a movable portion ofthe image stabilizing device is positioned in the vicinity of the centerof the correction lens.

A center of the coil for rotation can be regarded as a load generationpoint of the driving portion for rotation. Herein, the distance betweenthe rotary shaft and the load generation point of the driving portionfor rotation is longer than the distance between the rotary shaft andthe center of the correction lens. Therefore, it is possible to drivethe lens holding member using a small driving force, and thusminiaturization of the driving portion for rotation and a reduction inpower consumption can be achieved.

An image stabilizing device according to an eleventh invention has aconfiguration in which, in the device according to any one of the firstto ninth inventions, the driving portion for rotation has the magnet forrotation and a coil for rotation that is disposed so as to be opposed tothe magnet for rotation. When seen from the direction along the opticalaxis, a distance between the rotary shaft and the detection center ofthe position detection element for rotation is shorter than a distancebetween the rotary shaft and a center of the coil for rotation.

In this case, the movable area in the rotation direction of the positiondetection element for rotation becomes small. As a result, it becomeseasier for the movable area of the detection center of the positiondetection element for rotation to fall within the usable region of themagnet for rotation. Thus, it is possible to prevent deterioration inthe precision in position detection in the rotation direction.

An image stabilizing device according to a twelfth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to eleventh inventions, the rotary shaft is disposed ina region between the driving portion for rectilinear movement and thecorrection lens.

A portion of the correction lens holding member, to which the correctionlens is fixed, is required to have a strength sufficient to hold thecorrection lens. Accordingly, there is always part of the correctionlens holding member on the periphery of the correction lens.

Meanwhile, if the rotary shaft is disposed on the other side, the outerdimensions of the apparatus are increased by an amount determined by aportion in which the rotary shaft is formed.

Herein, the rotary shaft is disposed in the region between the drivingportion for rectilinear movement and the correction lens. Therefore, aspace on the periphery of the correction lens can be used effectively,and thus miniaturization of the apparatus can be achieved.

An image stabilizing device according to a thirteenth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to eleventh inventions, the driving portion forrectilinear movement is disposed in a region between the rotary shaftand the correction lens.

Particularly in the case where the position detection element forrectilinear movement that detects a position of the correction lensholding member in the rectilinear direction is provided on a straightline connecting the rotary shaft to the correction lens, compared withthe other arrangements, an error in the position detection forrectilinear movement that is caused due to rotation can be decreased.This allows the precision in correction in the rectilinear direction tobe improved.

An image stabilizing device according to a fourteenth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to thirteenth inventions, the position detectionelement for rectilinear movement that detects a position of thecorrection lens holding member in the rectilinear direction further isprovided. The driving portion for rectilinear movement has the magnetfor rectilinear movement and a coil for rectilinear movement that isdisposed so as to be opposed to the magnet for rectilinear movement. Adistance between the rotary shaft and the detection center of theposition detection element for rectilinear movement is shorter than adistance between the rotary shaft and a center of the coil forrectilinear movement.

In this case, the movable area in the rotation direction of the positiondetection element for rectilinear movement becomes small. As a result,it becomes easier for the movable area of the detection center of theposition detection element for rectilinear movement to fall within theusable region of the magnet. Thus, it is possible to secure theprecision in position detection in the rectilinear direction.

An image stabilizing device according to a fifteenth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to fourteenth inventions, a flexible printed board thatis connected electrically to the driving portion for rotation in orderto supply a voltage to the driving portion for rotation further isprovided. The flexible printed board has a first fixing portion that isfixed to the correction lens holding member, a second fixing portionthat is fixed to the lens holding member, and a flexible portion thatcouples the first fixing portion to the second fixing portion. Further,the flexible portion is disposed on a side of the rotary shaft relativeto the correction lens.

In this case, a deformation amount of the flexible portion when the lensholding member moves in the rotation direction is decreased, and thusdisconnection of the flexible printed board can be prevented. Further,when the deformation amount of the flexible portion is decreased, adriving force required to drive the lens holding member in the rotationdirection is decreased. Thus, this image stabilizing device can achievea reduction in power consumption.

An image stabilizing device according to a sixteenth invention has aconfiguration in which, in the device according to any one of the firstto fifteenth inventions, the correction lens is disposed in a regionbetween the driving portion for rotation and the driving portion forrectilinear movement.

In this case, when the image stabilizing device is seen from thedirection along the optical axis, the driving portion for rotation andthe driving portion for rectilinear movement are disposed on both sidesof the correction lens, respectively. Accordingly, the image stabilizingdevice has an increased length approximately in one direction. In otherwords, it is possible to reduce the dimension of the image stabilizingdevice in a direction orthogonal to a longitudinal direction. Thisallows an image stabilizing device to be adopted also in the case ofadopting a bending optical system.

Furthermore, also in a normal optical system, since the imagestabilizing device can be formed so as to have a long length in onedirection, a space can be formed in a short length direction, and thus amotor for operating a shutter, an iris, or the like can be disposed inthe space, thereby allowing a lens unit to be formed so as to have areduced thickness in an optical axis direction.

An image stabilizing device according to a seventeenth invention has aconfiguration in which, in the image stabilizing device according to anyone of the first to sixteenth inventions, at least three sets ofsupporting portions are provided. The supporting portions hold thecorrection lens member so that the correction lens member is movablefreely in the plane orthogonal to the optical axis and restrict aninclination thereof to either side of the direction along the opticalaxis.

As described above, the correction lens holding member is held withrespect to the lens holding member by at least three sets of supportingmembers provided in the lens holding member and the correction lensholding member, and thus an inclination amount of the correction lensmember can be reduced.

An image stabilizing device according to an eighteenth invention has aconfiguration in which, with respect to the seventeenth invention, acenter of gravity of the correction lens holding member is disposedwithin a diagram formed by connecting the three sets of supportingmembers, and thus a pressure applied on the three sets of supportingmembers can be dispersed. Therefore, when the correction lens holdingmember is in operation, a force is applied always on the three sets ofsupporting members. Thus, the correction lens holding member can be heldstably.

Particularly when, as in an image stabilizing device according to anineteenth invention, the center of gravity of the correction lensholding member is allowed to coincide substantially with a center ofgravity of the diagram formed by connecting the supporting members, abias load no longer is applied to the three sets of supporting members.This can suppress the occurrence of backlash/resonance, thereby allowingimage stabilization to be performed stably.

An image stabilizing device according to a twentieth invention has aconfiguration in which, in the image stabilizing device according to anyone of the seventeenth to nineteenth inventions, each of the at leastthree supporting portions has a first supporting portion that is formedin a rotary member and a second supporting portion that is formed in arotary holding member and can be engaged with the first supportingportion from a direction orthogonal to the rotary shaft. Further, one ofthe first supporting portion and the second supporting portion is arod-like body. Further, the other of the first supporting portion andthe second supporting portion is formed into a substantially U-shapedbody to be engaged with the rod-like body with a predetermined gap keptbetween the substantially U-shaped body and the rod-like body. Further,in an engaging gap portion between the first supporting portion and thesecond supporting portion, grease having a consistency of 310 to 340(JIS classification No. 1) is interposed to provide lubrication.

According to the above-described configuration, movement of the rotarymember with respect to the rotary holding member in the direction alongthe optical axis can be restricted using a simple configuration.Further, since grease having a consistency of 310 to 340 is interposedin the predetermined gap, a damping effect can be provided by theviscosity of the grease, and thus it is possible to suppressbacklash/resonance in the optical axis direction in the engaging gapportion between the first supporting portion and the second supportingportion.

A camera according to a twenty-first invention has a configuration inwhich, in the image stabilizing device according to any one of the firstto twentieth inventions, after the correction lens holding member thatholds the correction lens included in an optical system in order toperform image stabilization is assembled in the lens holding member, amovable area restriction member for restricting a movable area of thecorrection lens holding member is assembled in either of the correctionlens holding member and the lens holding member so as to prevent thecorrection lens holding member from being detached from the lens holdingmember. Further, it is possible to limit the movable area of thecorrection lens holding member with high precision. Further, comparedwith the case where a movable area correction member is formedintegrally with one of the correction lens holding member and the lensholding member, assembly processing can be improved.

A camera according to a twenty-second invention includes: a lens groupthat takes in light along an optical axis; an image stabilizing deviceas described in any one of the first to twenty-first inventions; animaging portion that receives light that has passed through the lensgroup; and a casing in which the lens group, the image stabilizingdevice, and the imaging portion are disposed. The casing holds a lensbarrel.

Herein, the expression “along the optical axis” means, for example,being parallel to the optical axis. Further, as the optical systemincluding the optical axis, in addition to a linear optical system, abending optical system can be used. The bending optical system can beconfigured to include, for example, a member having a reflectionsurface, more specifically, a prism, a mirror, or the like. Further, theimaging portion may be formed of, for example, a CCD, a CMOS, or thelike that electrically receives light with no limitation thereto, andalso may be formed of a film or the like.

This camera includes the image stabilizing device according to any oneof the first to twenty-first inventions and thus can achieveminiaturization while preventing deterioration in the image stabilizingperformance. This camera is significantly effective particularly inreducing a dimension in the optical axis direction. Further, in thiscamera adopting a bending optical system, the image stabilizing deviceaccording to the present invention having a reduced dimension in adirection orthogonal to a rectilinear direction can be incorporated.This allows a dimension of the camera (thickness of the camera) to bereduced. That is, this camera achieves miniaturization and can provide ahigh quality image obtained as a result of correcting image blurring.

A camera according to a twenty-third invention has a configuration inwhich, in the camera according to the twenty-second inventionincorporating the image stabilizing device of the tenth invention, adirection of rectilinear movement in the lens holding member of theimage stabilizing device is set to be substantially a perpendiculardirection with respect to a direction of gravity, so that an actuatorfor the rotation direction mainly is used during normal photographing,and thus power consumption of actuators can be reduced in accordancewith the principle of leverage. Particularly in a camera that is capableof photographing a moving image, the effect of reducing powerconsumption can be enhanced.

The terms used in the above description are explained as follows.

The “detection center of the position detection element” refers to anassumed point that can be regarded as one point at which the positiondetection element is disposed when performing position detection. Thedetection center can be, for example, a point in the position detectionelement at which maximum detection sensitivity is attained. Generally,the detection center can be assumed to be a central point on a detectionplane of the position detection element.

For example, in the case where the magnet is two-pole magnetized, the“usable region” refers to a performance guarantee area that is centeredon a polarization line between N and S poles and in which a magneticflux density changes at substantially a constant rate. Therefore, forexample, in the case where the magnet is two-pole magnetized, the“center line of the usable region” refers to a boundary line on whichpolarity changes between the N and S poles. Examples of the state of themagnet include, in addition to the case where an N-pole portion and aS-pole portion are physically integrated with each other, the case wherethe N-pole portion and the S-pole portion are separated from each otherphysically.

The “center of the coil” refers to a center determined based on an outershape of the coil, and, for example, in the case of a coil having theshape of substantially a quadrangle, it refers to a center of gravity ofthe quadrangle.

The position detection element can be, for example, a magnetic sensorutilizing a Hall effect (Hall element), a PSD (position sensitivedetector), or the like.

Embodiments 1. Outline of Present Embodiments

Hereinafter, embodiments of the present invention will be described withreference to FIGS. 1 to 15.

The digital cameras of the present invention are characterized mainly bya configuration of the image stabilizing device. Although the followingdescriptions of the digital cameras according to the present embodimentsare directed to a camera without a bending optical system, a bendingoptical system may be adopted as an optical system. That is, the digitalcameras according to the present embodiments can achieve a thicknessreduction, miniaturization, and a reduction in power consumption of anapparatus regardless of whether the apparatus has a configuration inwhich an optical system is bent or a configuration in which an opticalsystem is not bent.

2. Configuration of Digital Camera

A digital camera of a first embodiment of the present invention will bedescribed with reference to FIGS. 1 to 3.

[2-1. Specific Configuration of Digital Camera]

FIG. 1 is a perspective view showing an appearance of a digital camera 1of the first embodiment of the present invention.

The digital camera 1 includes an imaging apparatus 2 and a body portion3. The imaging apparatus 2 includes an optical system that leads a lightbeam, which has entered along an optical axis A, to an imaging elementat a fixed or freely changeable magnification. The body 3 houses theimaging apparatus 2 and performs, for example, control of the imagingapparatus 2.

Prior to describing a detailed configuration of the imaging apparatus 2,the following first describes a configuration of the body portion 3.

In the following description, six surfaces of the digital camera 1 aredefined as follows.

First, a “front surface” refers to a surface facing a subject side atthe time of photographing by the digital camera 1. A “back surface”refers to a surface on an opposite side of the front surface. An “uppersurface” refers to a surface facing an upper side in a verticaldirection in the case where photographing is performed in such a posturethat upper and lower sides of a subject in the vertical directioncoincide with upper and lower sides of a rectangular image captured bythe digital camera 1 (generally with an aspect ratio (ratio of a longside to a short side) of 3:2, 4:3, 16:9, etc.) in its short sidedirection. A “bottom surface” refers to a surface on an opposite side ofthe upper surface. A “left side surface” refers to a surface positionedon a left side when seen from a subject side in the case wherephotographing is performed in such a posture that upper and lower sidesof a subject in the vertical direction coincide with upper and lowersides of a rectangular image captured by the digital camera 1 in itsshort side direction. A “right side surface” refers to a surface on anopposite side of the left side surface. These definitions are notintended to limit the posture of the digital camera 1 when used.

Given the above-described definitions, it follows that FIG. 1 is aperspective view showing the front surface, the upper surface, and theleft side surface.

Not only the six surfaces of the digital camera 1, but also six surfacesof each constituent member disposed in the digital camera 1 are definedin the same manner. That is, the above-described definitions apply tothe six surface of each constituent member in a state of being disposedin the digital camera 1.

Furthermore, as shown in FIG. 1, with respect to a Y-axis parallel tothe optical axis A and an erect posture of the digital camera 1, anX-axis is defined to be in a horizontal direction and a Z-axis isdefined to be in a perpendicular direction. Moreover, as shown in FIG.1, a direction toward a front surface side from a back surface sidealong the optical axis A is defined as a Y-axis positive direction, adirection toward a left side surface side from a right side surface sideof the digital camera 1 is defined as an X-axis positive direction, anda direction toward an upper surface side from a bottom surface side ofthe digital camera 1 along an orthogonal axis orthogonal to the X- andY-axes is defined as a Z-axis positive direction.

The drawings referred to in the following description are based on thisXYZ coordinate system. That is, the X-axis positive direction, theY-axis positive direction, and the Z-axis positive direction in each ofthe drawings are the same as those in the other drawings, respectively.

[2-2. Configuration of Body Portion]

The description is directed to a configuration of the body portion 3with reference to FIGS. 1, 2, 3A, 3B, and 3C.

FIG. 2 is a perspective view showing an appearance of the back surface,the upper surface, and the right side surface of the digital camera 1.

FIGS. 3A to 3C are perspective diagrams schematically showing theconfiguration of the body portion 3. FIG. 3A is a perspective diagramshowing configurations of members disposed on the positive side in theY-axis direction (front surface side). FIG. 3B is a perspective diagramshowing configurations of members disposed on the negative side in theZ-axis direction (bottom surface side). FIG. 3C is a perspective diagramshowing configurations of members disposed on the negative side in theY-axis direction (back surface side).

As shown in FIGS. 1 to 3, the body portion 3 includes a housing portion11, a grip portion 12, a flash lamp 15, a release button 16, anoperation dial 17, an image display portion 18, a main capacitor 20, asub-substrate 21, a battery 22, and a main substrate 23. The housingportion 11 and the grip portion 12 constitute a housing that houses theimaging apparatus 2. The flash lamp 15, the release button 16, theoperation dial 17, and the image display portion 18 are disposed on thesurface of the housing portion 11. The main capacitor 20, thesub-substrate 21, the battery 22, and the main substrate 23 are disposedinside the housing constituted by the housing portion 11 and the gripportion 12. Further, a memory card 24 can be inserted into and removedfrom the body portion 3. A storage medium such as the memory card 24 maybe fixed inside the body portion 3 without being limited to theconfiguration in which it can be inserted into and removed from the bodyportion 3.

As shown in FIG. 1, the housing portion 11 is a housing havingsubstantially the shape of a rectangular solid. On the positive side inthe X-axis direction of the housing portion 11, the grip portion 12 fora photographer to grip is disposed so as to protrude in the Y-axisdirection from the housing portion 11. The housing portion 11 and thegrip portion 12 thus constitute a hollow housing having substantially anL shape. Further, the flash lamp 15 is disposed on the front surface ofthe housing portion 11. As necessary, for example, when a subject is ina dark environment, the flash lamp 15 flashes so that the subject isirradiated with light to aid in performing exposure. Further, on theside of the grip portion 12 of the upper surface of the housing portion11, the release button 16 and the operation dial 17 are disposed. Therelease button 16 receives a push-down operation toward the negativeside in the Z-axis direction by a user. With the operation dial 17,various settings such as a setting of a photographing operation can beperformed.

Moreover, as shown in FIG. 2, on the back surface of the housing portion11, the image display portion 18 (viewing portion) is provided thatallows a photographer or the like to view an image to be photographed bythe imaging apparatus 2. The image display portion 18 has, for example,a rectangular outer shape with an aspect ratio (ratio of a long side toa short side) of 3:2, 4:3, 16:9, etc.

In FIGS. 1 and 2, for clarity of illustration, only principal membersdisposed on the surface of the housing portion 11 are depicted.Accordingly, there may be provided members other than the members thathave been explained.

The description is directed next to an internal configuration of thebody portion 3 with reference to FIGS. 3A to 3C.

As shown in FIG. 3A, the imaging apparatus 2 holds a lens group G1facing a subject.

Moreover, on the positive side in the Z-axis direction of the imagingapparatus 2, the flash lamp 15, the main capacitor 20, and thesub-substrate 21 are disposed.

The main capacitor 20 applies flashing energy to the flash lamp 15 bycharging from the battery 22 that will be described later. Thesub-substrate 21 transforms power from the battery 22 that will bedescribed later from one voltage to another as required. Further, thesub-substrate 21 performs control of the flash lamp 15. Further, on thepositive side in the Y-axis direction inside the grip portion 12, thebattery 22 as a power supply for operating the digital camera 1 isdisposed.

Moreover, as shown in FIGS. 3B and 3C, on the negative side in theY-axis direction of the imaging apparatus 2, the main substrate 23 isdisposed. On the main substrate 23, an image processing circuit thatprocesses an image signal from the imaging apparatus 2, a controlcircuit for controlling the imaging apparatus 2, and the like aremounted. Further, on the negative side in the Y-axis direction of thebattery 22, the memory card 24 loaded in a memory card slot is disposed.The memory card 24 records an image signal from the imaging apparatus 2.

As shown in FIGS. 3A and 3B, the imaging apparatus 2 is formed so as tohave a width in the Z-axis direction (Wz) larger than its width in theY-axis direction (Wy).

3. Configuration of Imaging Apparatus

[3-1. Specific Configuration of Imaging Apparatus]

The following describes a configuration of the imaging apparatus 2incorporated in the digital camera 1 with reference to FIGS. 4, 5, and6.

FIG. 4 is a perspective assembly view of the imaging apparatus 2. FIG. 5is a view as seen from the side of the imaging element of the imagingapparatus 2. FIG. 6 is an exploded perspective view of the imagingapparatus 2 as seen from the same viewpoint as in FIG. 4.

The imaging apparatus 2 includes a lens barrel 31, a motor unit 32, anda master flange 33. The lens barrel 31 has an optical system. The motorunit 32 has a zoom motor 36 that drives the lens barrel 31. The masterflange 33 has a CCD 37 as an imaging portion that receives a light beamthat has passed through the lens barrel 31.

The motor unit 32 includes, for example, the zoom motor 36 such as a DCmotor, a flexible printed board (FPC) (not shown), and a photosensor(not shown). The FPC can electrically connect the zoom motor 36 to themain substrate 23 (see FIG. 3). The photosensor can determine theposition of a lens from an origin in the lens barrel 31 through themeasurement of motor revolutions of the zoom motor 36. The zoom motor 36drives the lens barrel 31 to move the optical system between a wideangle end and a telephoto end. Thus, the optical system included in thelens barrel 31 operates as a zoom lens system that changes amagnification at which an image of a light beam is formed on the CCD 37.

The master flange 33 includes the CCD 37, a CCD sheet metal 38, and aFPC 39. The CCD 37 can receive a light beam that has passed through thelens barrel 31 and convert it into an electric signal. The CCD sheetmetal 38 allows the CCD 37 to be fixed to the lens barrel 31. The FPC 39can electrically connect the CCD 37 to the main substrate 23 (see FIG.3).

4. Configuration of Lens Barrel

[4-1. Specific Configuration of Lens Barrel]

The following describes a configuration of the imaging apparatus 2,mainly a configuration of the lens barrel 31, with reference to FIG. 6.

The lens barrel 31 includes a first group frame unit 41, a second groupframe unit 42, an intermediate frame 43, a third group frame unit 44,and a fourth group frame unit 45. The first group frame unit 41 holds afirst lens group G1. The second group frame unit 42 holds a second lensgroup G2. The third group frame unit 44 holds an exposure adjustmentmember, a shutter, and a third lens group G3. The fourth group frameunit 45 holds a fourth lens group G4. The first group frame unit 41, thesecond group frame unit 42, the intermediate frame 43, the third groupframe unit 44, and the fourth group frame unit 45 are configured so asto be able to perform zooming and focusing operations under acollaborative operation between the intermediate frame 43 and a camgroove provided on a cam frame 46 by operations of a focus motor 35provided in the intermediate frame 43 and the zoom motor 36 provided atthe master flange 33.

[4-2. Configuration of Image Stabilizing Device]

(4-2-1. Overall Configuration of Image Stabilizing Device)

The description is directed first to an overall configuration of animage stabilizing device 400 with reference to FIGS. 7 to 10. FIG. 7 isan exploded perspective view of the image stabilizing device 400. FIG. 8is a perspective view showing a holding member and engaging portions ofthe image stabilizing device 400.

FIG. 9 is a perspective view of a correction lens holding member. FIG.10 is an exploded perspective view of a unit showing a positionalrelationship between the holding member and the correction lens holdingmember. FIG. 11 is an exploded perspective view of the image stabilizingdevice with the correction lens member assembled therein.

As shown in FIG. 7, the image stabilizing device 400 includes acorrection lens holding member 405, an electric substrate 406, and aholding member 408. The correction lens holding member 405 holds thethird lens group G3. The electric substrate 406 is fixed to thecorrection lens holding member 405. The holding member 408 supports thecorrection lens holding member 405 so that the correction lens holdingmember 405 is movable linearly in a yawing direction (X-axis direction).Further, the holding member 408 supports the correction lens holdingmember 405 so that the correction lens holding member 405 is movablelinearly in a pitching direction (Z-axis direction). Further, theholding member 408 supports the correction lens holding member 405 sothat the correction lens holding member 405 is rotatable about an axisparallel to the optical axis A.

As shown in FIG. 7, the correction lens holding member 405 is supportedso as to be movable in a plane orthogonal to the optical axis A, and arelative movement in the direction of the optical axis A is restricted.For this restriction, three restricting portions (supporting portions)are provided in a plane orthogonal to the X-axis. The three portions arepositioned so that a center of gravity of the correction lens holdingmember 405 lies within a triangle formed by connecting the threeportions in a X-Z plane.

Specifically, as shown in FIGS. 8 and 9, three first supporting portions483, 484, and 485 (see FIG. 8) are provided in the lens holding member408, and three second supporting portions 486, 487, and 488 (see FIG. 9)are provided in the correction lens holding member 405. The firstsupporting portion 483 has substantially a U shape open on the positiveside in the X-axis direction. Each of the first supporting portions 484and 485 has a rod-like body extending in the Z-axis direction.Meanwhile, the second supporting portions 486, 487, and 488 are disposedon the periphery of the third lens group G3. The second supportingportion 486 is a rod-like body extending in the Z-axis direction. Eachof the second supporting portions 487 and 488 has a substantiallyU-shaped portion open on the opposite side in the X-axis direction.

As shown in FIG. 10, the first supporting portions 483, 484, and 485 aredisposed in positions corresponding to the second supporting portions486, 487, and 488, respectively. Gaps in the Y-axis direction aresecured between the first supporting portions 483, 484, and 485 and thesecond supporting portions 486, 487, and 488, respectively. The secondsupporting portion 486 is engaged slidably with the first supportingportion 483. The second supporting portion 487 is engaged slidably withthe first supporting portion 484. The second supporting portion 488 isengaged slidably with the first supporting portion 485.

Furthermore, in an engaging gap portion between each of pairs of thefirst supporting portion 483 and the second supporting portion 486, thefirst supporting portion 484 and the second supporting portion 487, andthe first supporting portion 485 and the second supporting portion 488,grease (not shown) having a consistency of 310 to 340 is interposed toprovide lubrication.

The correction lens holding member 405 further has a rotary shaft A3.Meanwhile, the lens holding member 408 has a sliding groove 482extending linearly in the yawing direction (X-axis direction). Therotary shaft A3 is formed so as to have a diameter smaller than a groovewidth of the sliding groove 482 and is slidably and rotatably engagedwith the sliding groove 482.

Similarly, in an engaging gap portion between the rotary shaft A3 andthe sliding groove 482, grease (not shown) having a consistency of 310to 340 is interposed to provide lubrication.

Herein, the “pitching direction” refers to a direction along an arcabout the rotary shaft A3 (rotation direction), and the “yawingdirection” refers to the X-axis direction (rectilinear direction).

Moreover, as shown in FIG. 11, an electromagnetic actuator for rotation412 (see FIG. 7) for driving in the rotation direction is composed of ayoke 462 f, a magnet for fixing 462 e (see FIG. 8), a coil for rotation406 b, and an opposed yoke 462 h. The yoke 462 f is fixed to the lensholding member 408. The magnet for fixing 462 e is fixed to the yoke 462f and is two-pole magnetized in the Z-axis direction. The coil forrotation 406 b is fixed to the correction lens holding member 405. Thecoil for rotation 406 b is energized, and thus an electromagnetic powerFp in the pitching direction is generated.

Meanwhile, an electromagnetic actuator for rectilinear movement 413 (seeFIG. 7) for driving in the rectilinear direction is composed of a yoke462 d (see FIG. 8), a magnet for rotation 462 c, a coil for rectilinearmovement 406 a, and an opposed yoke 462 g. The yoke 462 d is fixed tothe holding member 408. The magnet for rotation 462 c is fixed to theyoke 462 d and is two-pole magnetized in the X-axis direction. The coilfor rectilinear movement 406 a is fixed to the magnet for rotation 462 cand to the correction lens holding member 405. The coil for rectilinearmovement 406 a is energized, and thus an electromagnetic power Fy in theyawing direction is generated.

On the positive side in the X-axis direction of the coil 406 b, a Hallelement 406 d (position detection element for rotation) for detecting amagnetic flux of the magnet 462 e so as to detect the position of thecorrection lens holding member 405 in the Z-axis direction is disposed.The Hall element 406 d uses the magnet 462 e that is used also by theelectromagnetic actuator for rotation 412.

Similarly, on the positive side in the Z-axis direction of the coil 406a, a Hall element 406 c (position detection element for rectilinearmovement) for detecting a magnetic flux of the magnet 462 c so as todetect the position of the correction lens holding member 405 in theX-axis direction is disposed. The Hall element 406 c uses the magnet 462c that is used also by the electromagnetic actuator for rectilinearmovement 413.

With respect to the electromagnetic actuator for rotation 412, the thirdlens group G3 is disposed on a side opposite to the side on which it isdisposed with respect to the electromagnetic actuator for rectilinearmovement 413. In other words, the third lens group G3 is disposed in aregion between the electromagnetic actuator for rotation 412 and theelectromagnetic actuator for rectilinear movement 413. The planararrangement of the constituent portions will be detailed later.

Furthermore, as shown in FIG. 10, the correction lens holding member 405further has a flexible printed board 490 for supplying a voltage to theelectric substrate 406. The flexible printed board 490 is connectedelectrically to the electric substrate 406.

[4-2-2. Positional Relationships among Portions of Image StabilizingDevice 400]

Furthermore, the image stabilizing device 400 is characterized also bypositional relationships among portions thereof. The following describesin detail the positional relationships among the portions with referenceto FIGS. 12 and 13. FIG. 12 is a schematic plan view of the correctionlens holding member 405 and the electric substrate 406 as seen from thepositive side in the Y-axis direction. FIG. 13 is a diagram forexplaining a magnet usable region and a Hall element performanceguarantee area. FIG. 12 shows a state where the optical axis A coincideswith a center C of the third lens group G3, that is, a state where thethird lens group G3 is positioned in the vicinity of a center of aregion in which the third lens group G3 is movable.

As shown in FIG. 12, in the state where the optical axis A coincideswith the center C of the third lens group G3, the Hall elements 406 cand 406 d and a center Pp of the coil 406 b of the image stabilizingdevice 400 are disposed in a plane including the rotary shaft A3 and thecenter C of the third lens group G3. That is, in a region in which thecorrection lens holding member 405 is movable, the rotary shaft A3, thecenter C of the third lens group G3, the Hall elements 406 c and 406 d,and the center Pp of the coil 406 b are disposed on a straight line Lextending in the X-axis direction.

Herein, the center Pp of the coil 406 b refers to a central point ofaction of a load generated by a collaborative operation between the coil406 b and the magnet 462 e when the coil 406 b is energized. The sameexplanation as that of the center Pp applies to a center Py of the coil406 a.

In the region in which the correction lens holding member 405 ismovable, there exists a state where a detection center Rp of the Hallelement 406 d coincides with a polarization line Qp of the magnet 462 e.In the state where the detection center Rp of the Hall element 406 dcoincides with the polarization line Qp of the magnet 462 e, thepolarization line Qp of the magnet 462 e is in a direction thatsubstantially coincides with the yawing direction (X-axis direction).Moreover, as shown in FIG. 12, in the state where the optical axis Acoincides with the center C of the third lens group G3, the detectioncenter Rp of the Hall element 406 d substantially coincides with thepolarization line Qp of the magnet 462 e.

Furthermore, in the state shown in FIG. 12, the rotary shaft A3, thecenter C of the third lens group G3, and a detection center Ry of theHall element 406 d are disposed approximately on the straight line L. Aline segment connecting the rotary shaft A3 to the detection center Ryof the Hall element 406 c substantially coincides with the yawingdirection (X-axis direction).

As shown in FIG. 12, a distance L1 between the rotary shaft A3 and thecenter Pp of the coil 406 b is longer than a distance L0 between therotary shaft A3 and the center C of the third lens group G3. A distanceL2 between the rotary shaft A3 and the detection center Rp of the Hallelement 406 d is shorter than the distance L1 between the rotary shaftA3 and the center Pp of the coil 406 b. A distance L3 between the rotaryshaft A3 and the detection center Ry of the Hall element 406 c isshorter than a distance L4 between the rotary shaft A3 and the center Pyof the coil 406 a.

Meanwhile, as shown in FIG. 12, in the region in which the correctionlens holding member 405 is movable, there exists a state where thedetection center Ry of the Hall element 406 c coincides with apolarization line Qy of the magnet 462 c. In the state where the opticalaxis A coincides with the center C of the third lens group G3, thedetection center Ry of the Hall element 406 c substantially coincideswith the polarization line Qy of the magnet 462 c.

In the state shown in FIG. 12, the polarization line Qp and the straightline L are substantially orthogonal to the direction of theelectromagnetic force Fp generated in the electromagnetic actuator 414.That is, in the state shown in FIG. 12, a plane including a point ofaction of the electromagnetic force Fp and the rotary shaft A3 issubstantially orthogonal to directions in which the electromagneticforce acts.

Herein, the “detection center of the Hall element” refers to an assumedpoint that can be regarded as one point at which the Hall element isdisposed when performing position detection. The detection center canbe, for example, a point in the Hall element at which maximum detectionsensitivity is attached. Generally, the detection center can be assumedto be a central point on a detection plane of the Hall element. The“polarization line of the magnet” refers to a boundary line on which thepolarity changes between the N and S poles. As shown in FIG. 13A, amagnetic flux density distribution of the magnet includes a usableregion centered on the polarization line, in which a magnetic fluxdensity changes at substantially a constant rate. The usable regionrefers to an area that can be used for position detection, and in theusable region, a measurement value of the Hall element changes with ameasurement position substantially linearly, thus allowing positiondetection to be performed with accuracy.

For example, as shown in FIG. 13B, in the magnet usable region, when arelative position (measurement position) between the Hall element andthe magnet changes, the measurement value (output) of the Hall elementchanges with a change in the relative position substantially linearly.Thus, based on the output of the Hall element, a relative position ofthe Hall element with respect to the magnet can be determined withaccuracy. That is, the magnet usable region corresponds to theperformance guarantee area with regard to position detection. When amovable area of the Hall element lies within this performance guaranteearea, the Hall element can endure the use as a position detectionelement for image stabilization.

In the case of the image stabilizing device 400, a magnetic flux densitydistribution in the yawing direction (X-axis direction) of the magnetfor rectilinear movement 462 c includes a usable region centered on thepolarization line Qy. A magnetic flux density distribution in thepitching direction (Z-axis direction) of the magnet for rotation 462 eincludes a usable region centered on the polarization line Qy. A movablearea of the detection center Ry of the Hall element 406 c is set so asto lie within the usable region of the magnet 462 c. A movable area ofthe detection center Ry of the Hall element 406 d is set so as to liewithin the usable region of the magnet 462 e.

[4-2-3. Method of Assembling Image Stabilizing Device 400]

The image stabilizing device 400 is characterized further by itsassembling method. The following describes the method of assembling theimage stabilizing device 400 with reference to FIGS. 10, 11, 14A, 14B,and 14C. FIGS. 14A, 14B, and 14C are diagrammatic views showing engagedstates between the first supporting portions and the second supportingportions.

As shown in FIG. 10, first, the correction lens holding member 405 isfitted to the surface of the lens holding member 408 on the positiveside in the Y-axis direction. At this time, as shown in FIGS. 14A and14B, the first supporting portions 487 and 488 of the correction lensholding member 405 are inserted into spaces on the peripheries of thesecond supporting portions 484 and 484 of the lens holding member 408,respectively, and the second supporting portion 483 is inserted into aspace on the periphery of the first supporting portion 486.

Next, as shown in FIG. 10, the correction lens holding member 405 isslid to the negative side in the X-axis direction with respect to thelens holding member 408. As a result of this, as shown in FIG. 14C,shaft portions of the second supporting portions 484 and 485 areinserted into the substantially U-shaped first supporting portions 487and 488, respectively, and a shaft portion of the first supportingportion 486 is inserted into the substantially U-shaped secondsupporting portion 483.

At the same time, the shaft A3 of the correction lens holding member 405is inserted into the sliding groove 482 of the lens holding member 408.

Further, as shown in FIG. 8, in the lens holding member 408, a bossportion 408 a is provided, into which a shaft A4 for restricting amountsof movement of the correction lens holding member 405 in the pitchingdirection and in the yawing direction on the X-Z plane is to be pressed.Meanwhile, as shown in FIGS. 9, 10, 11, and 12, in the correction lensholding member 405, a hole portion 405 a is provided in a positionopposed to the boss portion 408 a. The hole portion 405 a has a shapeable to collaborate with the shaft A4 in restricting amounts of movementof the correction lens holding member 405 in the pitching direction andin the yawing direction.

Thus, after the correction lens holding member 405 is mounted to thelens holding member 408, the movement amount restriction shaft A4 isthreaded through the hole portion 405 a of the correction lens holdingmember 405 from the positive side in the Y-axis direction so as to bepressed into or fixed by adhesion to the boss portion 408 a of the lensholding member 408 a.

As described above, the correction lens holding member 405 and the lensholding member 408 are engaged with each other by the first supportingportions 486, 487, and 488 and the second supporting portions 483, 484,and 485, thus forming a configuration in which movement of thecorrection lens holding member 405 in the Y direction is restricted,and, on the X-Z plane, the correction lens holding member 405 isrotatable about the rotary shaft A3 and is movable rectilinearly in theX direction. That is, unlike the conventional image stabilizing device,for example, there is no need to fix both ends of each of a yawing shaftand a pitching shaft by adhesion to a holding frame.

5. Effect

The image stabilizing device 400 described above provides the followingeffect.

(1). In the image stabilizing device 400, the correction lens holdingmember 405 is driven in the pitching direction (rotation direction)about the rotary shaft A3 with respect to the lens holding member 408.Further, the rotary shaft A3 is driven along the groove of the slidinggroove 482 provided in the lens holding member 408 in the yawingdirection (in the rectilinear direction). This eliminates the need forshafts for guiding in the pitching direction and in the yawingdirection. Thus, a reduction in the dimension in the perpendicularZ-axis direction, the pitching direction, can be achieved.

(2). In the image stabilizing device 400, in the state where thedetection center Rp of the Hall element 406 d coincides with thepolarization line Qp of the magnet 462 e, the polarization line Qp ofthe magnet 462 e is in a direction that substantially coincides with theyawing direction (rectilinear direction). Therefore, when the correctionlens holding member 405 is driven in the yawing direction, a positionalshift in the yawing direction (rectilinear direction) between thedetection center Rp of the Hall element 406 d and the polarization lineQp of the magnet 462 e is suppressed. As a result, it becomes easier forthe movable area of the detection center Rp of the Hall element 406 d tofall within the usable region of the magnet 462 e. Thus, it is possibleto prevent deterioration of the precision in position detection in theyawing direction due to movement in the pitching direction.

Herein, the case where “the polarization line Qp of the magnet 462 e isin a direction that substantially coincides with the yawing direction(X-axis direction)” refers also to, in addition to the case where thepolarization line Qp completely coincides with the yawing direction, acase where, in the state where the movable area of the detection centerRp of the Hall element 406 d lies within the usable region of the magnet462 e, the polarization line Qp and the yawing direction are shiftedfrom each other.

(3). In the image stabilizing device 400, in the state where the centerC of the third lens group G3 coincides with the optical axis A, thedetection center Rp of the Hall element 406 d substantially coincideswith the polarization line Qp of the magnet 462 e. Therefore, in thestate where the center C of the third lens group G3 coincides with theoptical axis A, it becomes easier for an area of the detection center Rpof the Hall element 406 d to fall within the usable region of the magnet462 e. Thus, it is possible to prevent deterioration of the precision inposition detection in the yawing direction.

Herein, the case where “the detection center Rp of the Hall element 406d substantially coincides with the polarization line Qp of the magnet462 e” refers also to, in addition to the case where the detectioncenter Rp completely coincides with the polarization line Qp, a casewhere, in the state where the movable area of the detection center Rp ofthe Hall element 406 d lies within the usable region of the magnet 462e, the detection center Rp and the polarization line Qp are shifted fromeach other.

(4). In the image stabilizing device 400, the rotary shaft A3, thecenter C of the third lens group G3, and the detection center Rp of theHall element 406 d are disposed approximately on the straight line L.Therefore, when the correction lens holding member 405 is driven in theyawing direction, a positional shift between the detection center Rp ofthe Hall element 406 d and the polarization line Qp of the magnet 462 eis suppressed. As a result, it becomes easier for the movable area ofthe detection center Rp of the Hall element 406 d to fall within theusable region of the magnet 462 e. Thus, it is possible to preventdeterioration of the precision in position detection in the yawingdirection.

Herein, the case where “the rotary shaft A3, the center C of the thirdlens group G3, and the detection center Rp of the Hall element 406 d aredisposed approximately on one straight line L” refers also to, inaddition to the case where the rotary shaft A3, a center of the opticalaxis, and the detection center Rp are disposed on one straight line, acase where, in the state where the movable area of the detection centerRp of the Hall element 406 d lies within the usable region of the magnet462 e, the rotary shaft A3, the center of the optical axis, and thedetection center Rp are shifted from one another.

(5). In the image stabilizing device 400, a line segment connecting therotary shaft A3 to the detection center Ry of the Hall element 406 csubstantially coincides with the yawing direction (X-axis direction).Therefore, in the state where the optical axis A coincides with thecenter C of the third lens group G3, it becomes easier for the movablearea of the detection center Ry of the Hall element 406 c to fall withinthe usable region of the magnet 462 e. Thus, it is possible to preventdeterioration of the precision in position detection in the pitchingdirection. Herein, the case where “a line segment connecting the rotaryshaft A3 to the detection center Ry of the Hall element 406 csubstantially coincides with the yawing direction” refers also to, inaddition to the case where this line segment completely coincides withthe yawing direction, a case where, in the state where the movable areaof the detection center Ry of the Hall element 406 c lies within theusable region of the magnet 462 e, this line segment and the yawingdirection are shifted from each other.

(6). In the image stabilizing device 400, in the state where the opticalaxis A coincides with the center C of the third lens group G3, thedetection center Ry of the Hall element 406 c substantially coincideswith the polarization line Qy of the magnet 462 c. Therefore, when thecorrection lens holding member 405 is driven in the pitching direction,a positional shift between the detection center Ry of the Hall element406 c and the polarization line Qy of the magnet 462 c is suppressed. Asa result, it becomes easier for the movable area of the detection centerRy of the Hall element 406 c to fall within the usable region of themagnet 462 c. Thus, it is possible to prevent deterioration of theprecision in position detection in the pitching direction.

Herein, the case where “the detection center Ry of the Hall element 406c substantially coincides with the polarization line Qy of the magnet462 c” refers also to, in addition to the case where the detectioncenter Ry completely coincides with the polarization line Qy, a casewhere, in the state where the movable area of the detection center Ry ofthe Hall element 406 c lies within the usable region of the magnet 462e, the detection center Ry and the polarization line Qy are shifted fromeach other.

(7). In the image stabilizing device 400, the distance L1 between therotary shaft A3 and the center Pp of the coil 406 b is longer than thedistance LO between the rotary shaft A3 and the center C of the thirdlens group G3. Therefore, a center of gravity of a portion of the imagestabilizing device 400, which is movable in the yawing direction(portion constituted by the pitching movement frame 405, the yawingmovement frame 408, and the like), is positioned in the vicinity of thecenter C of the third lens group G3 when seen from the Y-axis direction.

For example, it is assumed that when a self-weight W [N] of the movableportion acts on the negative side in the Z-axis direction, a center ofgravity of the movable portion of the image stabilizing device 400 ispositioned in the vicinity of the center C of the third lens group G3.Where a distance from the rotary shaft A3 to a point of action of theself-weight W is denoted as L [m] and a distance from the rotary shaftA3 to the center Pp of the coil 406 b is denoted as L1 [m], by momentequilibrium, the electromagnetic force Fp [N] required in theelectromagnetic actuator for rotation 414 in order to support theself-weight W is expressed as follows.

Fp×L1=W×L

As shown in FIG. 12, since L<L1, a relationship Fp<W is established.That is, it is possible to perform driving in the pitching directionusing a driving force smaller than a force required to support the realweight.

According to the above-described configuration, compared with the caseof the conventional image stabilizing device, a smaller electromagneticforce can be used as the electromagnetic force Fp required in theelectromagnetic actuator for rotation 414. This allows miniaturizationof the electromagnetic actuator for rotation 414 to be achieved andpower consumption of the image stabilizing device 400 to be reduced.

Particularly in the case where, as has been explained in this example,the electromagnetic actuator for rectilinear movement is used forcorrection in the yawing direction and the electromagnetic actuator forrotation is used for correction in the pitching direction, it ispossible to achieve a significant effect of reducing power consumptionin a camera apparatus using the image stabilizing device 400.

(8). In the image stabilizing device 400, the distance L2 between therotary shaft A3 and the detection center Rp of the Hall element 406 d isshorter than the distance L1 between the rotary shaft A3 and the centerPp of the coil 406 b. Therefore, a movable area of the Hall element 406d in the pitching direction is decreased, so that it is possible toallow the movable area of the detection center Rp of the Hall element406 d to fall within the usable region of the magnet 462 e. Thus, it ispossible to prevent deterioration of the precision in position detectionin the pitching direction.

(9). In the image stabilizing device 400, with respect to the rotaryshaft A3, the electromagnetic actuator for rectilinear movement 413, thethird lens group G3, and the electromagnetic actuator for rotation 412are arranged in this order on the negative side in the X-axis direction.Herein, where a movement amount of a correction lens is denoted as α, aposition detection error Ps_1 of the Hall element 406 c, which is aposition detection element for rectilinear movement, due to rotation canbe expressed by:

Ps _(—)1=(L0_(—)1−L3_(—)1)×(1−cos(sin−1(α/L0_(—)1))).

Meanwhile, in the case of an arrangement of the constituent elements ina second example, i.e. the case where, with respect to the rotary shaftA3, the electromagnetic actuator for rectilinear movement 413 isarranged on the positive side in the X-axis direction, and the thirdlens group G3 and the electromagnetic actuator for rotation 412 arearranged in this order on the negative side in the X-axis direction,similarly, a position detection error Ps_2 of the Hall element 406 c canbe expressed by:

Ps _(—)2=(L0_(—)2+L3_(—)2)×(1−cos(sin−1(α/L0_(—)1))).

Herein, in order to obtain correction lens holding members ofsubstantially the same size as the correction lens holding members 405,for example, the following values are set.

α=0.2 [mm]

L0_1=15 [mm]

L3_1=5 [mm]

L0_2=7 [mm]p L3_2=5 [mm]0

In this case, the position detection errors in the respectivearrangements are determined as follows:

Ps_1=0.001 [mm]

Ps_2=0.005 [mm].

Thus, arcs formed by movement tracks of the detection center Rp of theHall element 406 d and the detection element Ry of the Hall element 406c, which result from the correction lens holding member 405 beingrotated about the rotary shaft A3 by the action of the electromagneticactuator for rotation 412, are in the same direction with respect to therotary shaft A3, and thus a positional shift in the rectilineardirection caused due to rotation can be reduced.

Thus, it is possible to prevent deterioration of the precision inposition detection in the rectilinear direction.

(10). In the image stabilizing device 400, the distance L3 between therotary shaft A3 and the detection center Ry of the Hall element 406 c isshorter than the distance L4 between the rotary shaft A3 and the centerPy of the coil 406 c. Therefore, a movable area in the pitchingdirection of the Hall element 406 c is smaller than a movable area inthe pitching direction of the coil 406 a. As a result, it is possible toallow the movable area of the detection center Ry of the Hall element406 c to fall within the usable region of the magnet 462 c. Thus, it ispossible to prevent deterioration of the precision in position detectionin the yawing direction.

(11). In the image stabilizing device 400, a flexible portion 492 of theflexible printed board 490 is disposed on the side of the rotary shaftA3 relative to the third lens group G3. Therefore, a deformation amountof the flexible portion 492 in the case where the correction lens member405 moves in the pitching direction can be minimized, and thusdisconnection of the flexible printed board 490 can be prevented.

Furthermore, when the deformation amount of the flexible portion 492 isdecreased, a driving force required to drive the correction lens holdingmember 405 in the pitching direction is decreased. Thus, the imagestabilizing device 400 can achieve a reduction in power consumption.

(12). In the image stabilizing device 400, the third lens group G3 isdisposed in a region between the electromagnetic actuator for rotation414 and the electromagnetic actuator for rectilinear movement 412. Thatis, the electromagnetic actuator for rectilinear movement 412 and theelectromagnetic actuator for rotation 414 are disposed on both sides ofthe third lens group G3, respectively. Accordingly, the imagestabilizing device 400 has an increased length generally in onedirection (the X-axis direction as the yawing direction in thisembodiment). In other words, it is possible to reduce the dimension inthe Z-axis direction (pitching direction) orthogonal to the X-axisdirection.

(13). In the image stabilizing device 400, the correction lens holdingmember 405 and the lens holding member 408 are engaged with each otherby the first supporting portions 486, 487, and 488 and the secondsupporting portions 483, 484, and 485, thus forming a configuration inwhich movement of the correction lens holding member 405 in the Ydirection is restricted, and, on the X-Z plane, the correction lensholding member 405 is rotatable about the rotary shaft A3 and is movablerectilinearly in the X direction.

Furthermore, one of each pair composed of one of the first supportingportions and one of the second supporting portions is formed to be arod-like body, while the other is formed in substantially a U shape.According to this configuration, it is possible to restrict movement ofthe correction lens holding member 405 in the direction of the opticalaxis A with respect to the lens holding member 408. Further, thecorrection lens holding member 405 is supported in the pitchingdirection and in the yawing direction using a single-stageconfiguration, and thus compared with the conventional image stabilizinglens having a two-stage configuration, it is possible to reduce aninclination of the correction lens holding member 405 with respect tothe perpendicular direction of the optical axis A.

Although in this example, one of each pair composed of one of the firstsupporting portions and one of the second supporting portions is formedto be a rod-like body, while the other is formed in substantially a Ushape, the supporting may be achieved without limitation thereto. Forexample, one of each pair composed of one of the first supportingportions and one of the second supporting portions may take the form ofa plate-shaped elastic body, while the other may have a cylindricalshape or a spherical shape.

(14). Furthermore, in the image stabilizing device 400, in an engaginggap portion between each of pairs of the first supporting portion 483and the second supporting portion 486, the first supporting portion 484and the second supporting portion 487, and the first supporting portion485 and the second supporting portion 488, grease (not shown) having aconsistency of 310 to 340 is interposed to provide lubrication.

This allows the correction lens holding member 405 to move on the X-Zplane smoothly. Further, this can provide a damping effect ofsuppressing swings in the Y-axis direction in the engaging gap portionbetween each of the pairs of the first supporting portion 483 and thesecond supporting portion 486, the first supporting portion 484 and thesecond supporting portion 487, and the first supporting portion 485 andthe second supporting portion 488.

In the case of using, as one example, grease mainly containingperfluoropolyether (PFPE) as a base oil and polytetrafluoroethylene(PTFE) as a thickening agent and set to have a consistency of 310 to340, it is possible to decrease frictional resistance (decrease powerconsumption). Further, interposing the grease in the engaging portionallows the damping effect to be exerted by the viscosity of the greasewith respect to backlash caused due to a gap in the engaging portionbetween each pair of the supporting portions.

Herein, FIGS. 15A to 15D are diagrams showing the damping effectprovided by grease. FIGS. 15A and 15B show graphs of measurement resultsof open-loop characteristics of the image stabilizing device in whichgrease having a consistency of 355 to 385 is applied. FIGS. 15C and 15Dshow graphs of measurement results of the open-loop characteristics ofthe image stabilizing device in which grease having a consistency of 310to 340 is applied. As shown in FIGS. 15A and 15B, the case of applyingthe grease having a consistency of 355 to 385 exhibits the occurrence ofresonance at a frequency of 350 Hz. Meanwhile, as shown in FIGS. 15C and15D, the case of applying the grease having a consistency of 310 to 340exhibits no such occurrence of resonance at a frequency of 350 Hz. Thisexplains that the damping effect can be exerted by adjusting theconsistency of grease.

The type of grease used is not restricted to the above-describedexample. Although the grease containing PFPE as a base oil and PTFE as athickening agent has been presented as one example, grease containing anolefin-based synthetic oil as a base oil and lithium soap as athickening agent also can be used.

Moreover, in the above-described example, a sliding portion has a gap ofabout 7 to 20 μm as one example. Generally, when grease having aconsistency lower than 310 is applied, while a viscous load of thesliding portion is increased to allow the damping effect to be enhanced,it is conceivable that the power consumption of the image stabilizingdevice could be increased. The consistency of grease may be adjustedbased on a gap of the sliding portion and a required dampingcharacteristic, load characteristics represented by power consumption,sliding characteristics, or the like.

Furthermore, an optimum consistency of grease to be applied may varydepending on the size of a gap of the engaging gap portion and amaterial used for the engaging portion.

(15). In the image stabilizing device 400, the yawing direction of thecorrection lens holding member 405 is determined by the sliding groovein the yawing direction (X direction) formed in the lens holding member408 to which an imaging element such as a CCD is fixed. Therefore, ashift between the X direction of the imaging element such as a CCD andthe yawing direction with respect to which correction is performed bythe correction lens holding member 405 can be reduced, thereby allowingthe precision in image stabilization to be enhanced.

(16). The method of manufacturing the image stabilizing device 400basically makes it possible to assemble the image stabilizing device 400without performing a process such as of adhesion, and thus improvedprecision and simplification of processes can be achieved. Further, thenumber of processes can be reduced, thereby allowing a manufacturingcost to be reduced.

(17). In the method of manufacturing the image stabilizing device 400,after the correction lens holding member 405 is assembled to the lensholding member 408, the shaft A4 is pressed into or fixed by adhesion tothe boss portion 408 a formed in the lens holding member 408, and thusareas of movement of the correction lens holding member 405 in thepitching direction and in the yawing direction with respect to the lensholding member 408 are restricted, thereby allowing restriction of theareas of movement to be preformed with precision.

(18). Although this example has been described based on an opticalsystem by which light enters an imaging element such as a CCD with itsoptical axis being straight without being bent, a bending optical systemalso may be used as the optical system, in which case the thicknessreduction of a camera apparatus can be achieved.

(19). Although in this example, image stabilization is performed withthe rectilinear direction set to be the yawing direction and therotation direction set to be the pitching direction, the directions alsomay be reversed, i.e. the directions can be set so that the rectilineardirection is the pitching direction and the rotation direction is theyawing direction. That is, the driving method and arrangement of theactuators are not limited by the directions with respect to whichcorrection is performed.

(20). Although in this example, the electromagnetic actuators areconfigured by providing the correction lens holding member 405 withcoils and by providing the lens holding member 408 with magnets, theconfigurations of the electromagnetic actuators are not limited thereto.

For example, as shown in FIG. 16, actuators can be configured byproviding the correction lens holding member 405 with magnets and byproviding the lens holding member 408 with coils 406 a and 406 b.

FIG. 16 is a perspective view of an image stabilizing device with amodified actuator magnetic circuit as one example. In this drawing, thesame components as in the image stabilizing device shown in FIG. 7 aredenoted by the same reference numerals.

As shown in FIG. 16, in an image stabilizing device 400, the coil 406 aand the coil 406 b are fixed to a lens holding member 408. Whenenergized, the coil 406 b allows a correction lens holding member 405 tobe driven to be rotated about a rotary shaft A3. The coil 406 a allowsthe correction lens holding member 405 to be driven to moverectilinearly in the Z-axis direction. Moreover, in the imagestabilizing device 400, position detection elements 406 c and 406 d,which are formed of a Hall element or the like, are fixed via a flexibleboard (not shown) in positions opposed to a magnet for rotation 462 eand a magnet for rectilinear movement 462 c, respectively.

Furthermore, the magnet for rotation 462 e that is two-pole magnetizedin the Z-axis direction and the magnet for rectilinear movement 462 cthat is two-pole magnetized in the X-axis direction are fixed to thecorrection lens holding member 405 holding a third lens group G3.

The correction lens holding member 405 further has the rotary shaft A3.Meanwhile, the lens holding member 408 has a sliding groove 482 (notshown) extending linearly in the pitching direction (Y-axis direction).The rotary shaft A3 is formed so as to have a diameter smaller than agroove width of the sliding groove 482 and is slidably and rotatablyengaged with the sliding groove 482.

As shown in FIG. 16, the correction lens holding member 405 is supportedso as to be movable in a plane orthogonal to an optical axis A, and arelative movement in the direction of the optical axis A is restricted.For this restriction, three restricting portions (supporting portions)(substantially U-shaped supporting portions 483, 487, and 488) areprovided in a plane orthogonal to the X-axis. Moreover, the threeportions are positioned so that a center of gravity of the correctionlens holding member 405 lies within a triangle defined by connecting thethree portions in a X-Z plane.

Moreover, in this configuration, non⁻magnetic metal shafts 485 and 486having a diameter smaller than a width of an opening of each of thesubstantially U-shaped supporting portions 483, 487, and 488 areslidably engaged with opening portions of the substantially U-shapedsupporting portions 483, 487, and 488, after which they are pressed intoand fixed by means of, for example, adhesion, to the lens holding member408. Thus, the correction lens holding member 405 is supported so thatit is movable linearly in the pitching direction (Z-axis direction), itis movable in the yawing direction (X-axis direction), and it isrotatable about an axis parallel to the optical axis A.

With this configuration adopted, the coils 406 a and 406 b are fixed tothe lens holding member 408 (fixed portion), and thus a flexible printedboard having a flexible portion no longer is needed, thereby reducingthe cost. Further, this configuration prevents the correction lensholding member 405 from being biased in one direction due to theelasticity of the flexible portion of the flexible board, therebyallowing controllability to be improved.

In addition, this configuration prevents the flexible portion of theflexible board from being subjected repeatedly to a load due to movementof the correction lens holding member 405, and thus disconnection of theflexible board can be prevented, thus leading to improved reliability.

(21). Although this example has been explained using electromagneticactuators as the actuators, the configuration of the actuators is notlimited to an electromagnetic actuator, and the actuators can be formedalso of an actuator using vibrations of a piezoelectric element, a motorsuch as a stepping motor, or the like.

6. Second Configuration Example of Image Stabilizing Device

Although in the above-described image stabilizing device 400, withrespect to the rotary shaft A3, the electromagnetic actuator forrectilinear movement 413, the third lens group G3, and theelectromagnetic actuator for rotation 412 are arranged in this order onthe negative side in the X-axis direction, an arrangement also may beadopted, in which, as shown in FIG. 17, with respect to the rotary shaftA3, the electromagnetic actuator for rectilinear movement 413 isarranged on the positive side in the X-axis direction, and the thirdlens group G3 and the electromagnetic actuator for rotation 412 arearranged in this order on the negative side in the X-axis direction.

In an image stabilizing device 400 adopting the above-describedarrangement, a portion of the correction lens holding member 405, towhich the third lens group G3 is fixed, is required to have sufficientstrength to hold the third lens group G3. Accordingly, there is alwayspart of the correction lens holding member 405 on the periphery of thethird lens group G3. In this embodiment, when the image stabilizingdevice 400 is seen from the Y-axis direction, the third lens group G3 issurrounded by the correction lens holding member 405. The rotary shaftA3 is disposed in a region between the electromagnetic actuator forrectilinear movement 412 and the third lens group G3. Therefore, a spaceon the periphery of the third lens group G3 can be used effectively, andthus miniaturization of an apparatus can be achieved. Particularly, thedimension in the X-axis direction can be reduced.

As described above, in order to reduce a position detection error in therectilinear direction caused due to rotation, it is preferable toincorporate an image stabilizing device having the first configurationin a camera apparatus. Further, in the case where an image stabilizingdevice having a reduced dimension in its longitudinal direction isrequired, it is preferable to incorporate an image stabilizing devicehaving the second configuration in a camera apparatus. That is, anarrangement of the rotary shaft A3, the electromagnetic actuator forrectilinear movement 413, the third lens group G3, and theelectromagnetic actuator for rotation 412 could be adopted selectivelydepending on a specification required of a camera apparatus.

INDUSTRIAL APPLICABILITY

The image stabilizing device and camera according to the presentinvention are useful in the field related to a camera required toachieve miniaturization and to provide image stabilizing performance.

1. An image stabilizing device having a correction lens for correctingimage blurring attributable to movement of a camera, the devicecomprising: a rotary shaft substantially parallel to an optical axis oflight entering the correction lens; a correction lens holding member towhich the a correction lens included in an optical system of the camerais fixed; a holding member that holds the correction lens holding memberso that the correction lens holding member is movable rectilinearly in arectilinear direction that is an arbitrary direction in a planeorthogonal to the optical axis of light entering the correction lens andso that the correction lens holding member is rotatable in a rotationdirection about the rotary shaft in the plane; a driving portion forrectilinear movement that applies a driving force to the correction lensholding member in order to drive the correction lens holding member inthe rectilinear direction; and a driving portion for rotation thatapplies a driving force to the correction lens holding member in orderto drive the correction lens holding member in the rotation direction.2. The image stabilizing device according to claim 1, wherein theholding member comprises a groove that is formed in the rectilineardirection in the plane, and the rotary shaft is engaged with the grooveso that the rotary shaft is movable along the groove.
 3. The imagestabilizing device according to claim 1, further comprising a positiondetection element for rotation that detects a position of the correctionlens holding member in the rotation direction, wherein the drivingportion for rotation has a magnet for rotation, a magnetic flux densitydistribution in the rotation direction of the magnet for rotationincludes a usable region for rotation in which a magnetic flux densitychanges at substantially a constant rate, when seen from a directionalong the optical axis, there exists a state where, in a region in whichthe correction lens holding member is movable, a detection center of theposition detection element for rotation coincides with a center line ofthe usable region for rotation in the rotation direction, and either ofthe position detection element for rotation and the magnet for rotationis formed integrally with the correction lens holding member.
 4. Theimage stabilizing device according to claim 3, wherein, when seen fromthe direction along the optical axis, in the state where the detectioncenter of the position detection element for rotation coincides with thecenter line of the usable region for rotation in the rotation direction,a direction of the center line of the usable region for rotation in therotation direction substantially coincides with the rectilineardirection.
 5. The image stabilizing device according to claim 3,wherein, when seen from the direction along the optical axis, in a statewhere the optical axis of light entering the correction lens coincideswith a center of the correction lens, the detection center of theposition detection element for rotation substantially coincides with thecenter line of the usable region for rotation in the rotation direction.6. The image stabilizing device according to claim 3, wherein, when seenfrom the direction along the optical axis, the rotary shaft, the centerof the correction lens, and the detection center of the positiondetection element for rotation are disposed on substantially a straightline.
 7. The image stabilizing device according to claim 1, furthercomprising a position detection element for rectilinear movement thatdetects a position of the correction lens holding member in therectilinear direction, wherein, when seen from the direction along theoptical axis, a line segment connecting the rotary shaft to a detectioncenter of the position detection element for rectilinear movementsubstantially coincides with the rectilinear direction.
 8. The imagestabilizing device according to claim 1, further comprising a positiondetection element for rectilinear movement that detects a position ofthe correction lens holding member in the rectilinear direction, whereinthe driving portion for rectilinear movement has a magnet forrectilinear movement, a magnetic flux density distribution in therectilinear direction of the magnet for rectilinear movement includes ausable region for rectilinear movement in which a magnetic flux densitychanges at substantially a constant rate, and when seen from thedirection along the optical axis, there exists a state where, in theregion in which the correction lens holding member is movable, adetection center of the position detection element for rectilinearmovement coincides with a center line of the usable region forrectilinear movement in the rectilinear direction.
 9. The imagestabilizing device according to claim 8, wherein, when seen from thedirection along the optical axis, in the state where the optical axis oflight entering the correction lens coincides with the center of thecorrection lens, the detection center of the position detection elementfor rectilinear movement substantially coincides with the center line ofthe usable region for rectilinear movement in the rectilinear direction.10. The image stabilizing device according to claim 1, wherein thedriving portion for rotation has a magnet for rotation and a coil forrotation that is disposed so as to be opposed to the magnet forrotation, and when seen from the direction along the optical axis, adistance between the rotary shaft and a center of the coil for rotationis longer than a distance between the rotary shaft and the center of thecorrection lens.
 11. The image stabilizing device according to claim 1,further comprising a position detection element for rotation thatdetects a position of the correction lens member in the rotationdirection, wherein the driving portion for rotation has a magnet forrotation and a coil for rotation that is disposed so as to be opposed tothe magnet for rotation, and when seen from the direction along theoptical axis, a distance between the rotary shaft and the detectioncenter of the position detection element for rotation is shorter than adistance between the rotary shaft and a center of the coil for rotation.12. The image stabilizing device according to claim 1, wherein therotary shaft is disposed in a region between the driving portion forrectilinear movement and the correction lens.
 13. The image stabilizingdevice according to claim 7, wherein the position detection element forrectilinear movement is disposed in a region between the rotary shaftand the correction lens.
 14. The image stabilizing device according toclaim 1, further comprising a position detection element for rectilinearmovement that detects a position of the correction lens holding memberin the rectilinear direction, wherein the driving portion forrectilinear movement has a magnet for rectilinear movement and a coilfor rectilinear movement that is disposed so as to be opposed to themagnet for rectilinear movement, and a distance between the rotary shaftand the detection center of the position detection element forrectilinear movement is shorter than a distance between the rotary shaftand a center of the coil for rectilinear movement.
 15. The imagestabilizing device according to claim 1, further comprising a flexibleprinted board that is connected electrically to the driving portion forrectilinear movement and the driving portion for rotation in order tosupply a voltage to the driving portion for rectilinear movement and tothe driving portion for rotation, respectively, wherein the flexibleprinted board has a fixing portion that is fixed to the lens holdingmember and a flexible portion that couples the fixing portion and isdeformable, and the flexible portion is disposed on a side of the rotaryshaft relative to the correction lens.
 16. The image stabilizing deviceaccording to claim 1, wherein the correction lens is disposed in aregion between the driving portion for rotation and the driving portionfor rectilinear movement.
 17. The image stabilizing device according toclaim 1, wherein the holding member comprises at least three supportingportions that hold the correction lens holding member so that thecorrection lens holding member is movable freely in the plane orthogonalto the optical axis and restrict movement of the correction lens holdingmember to either side of the direction along the optical axis.
 18. Theimage stabilizing device according to claim 17, wherein a center ofgravity of the correction lens holding member lies within a diagramformed by connecting the supporting portions.
 19. The image stabilizingdevice according to claim 18, wherein the center of gravity of thecorrection lens holding member substantially coincides with a center ofgravity of the diagram formed by connecting the supporting portions. 20.The image stabilizing device according to claim 17, wherein each of theat least three sets of supporting portions has a first supportingportion that is formed in the correction lens holding member and asecond supporting portion that is formed in the lens holding member andcan be engaged with the first supporting portion from a directionorthogonal to the rotary shaft, one of the first supporting portion andthe second supporting portion is a rod-like body, the other of the firstsupporting portion and the second supporting portion is a substantiallyU-shaped body to be engaged with the rod-like body with a predeterminedgap kept between the substantially U-shaped body and the rod-like body,and grease having a consistency of 310 to 340 is interposed in theengaging gap portion.
 21. The image stabilizing device according toclaim 1, wherein, after the correction lens holding member that holdsthe correction lens included in the optical system in order to performimage stabilization is assembled in the lens holding member, a movablearea restriction member for restricting a movable area of the correctionlens holding member is assembled in either of the correction lensholding member and the lens holding member.
 22. (canceled) 23.(canceled)
 24. The image stabilizing device according to claim 1,wherein the holding member comprises at least three sets of supportingportions that restrict movement of the correction lens holding member toeither side of the direction along the optical axis.
 25. The imagestabilizing device according to claim 24, wherein each of the at leastthree sets of supporting portions has a first supporting portion that isformed in the holding member and a second supporting portion that isformed in the correction lens holding member and can be engaged with thefirst supporting portion with a predetermined gap from a directionorthogonal to the rotary shaft.
 26. The image stabilizing deviceaccording to claim 25, wherein grease is interposed in the gap.